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Originally Posted by esteem_lover rangaraj,
thanks a lot. ur post was very informative. like u said about the picture quality depends on the bandwidth allocated, i have a few questions here.
i think u r a technical guy, so if u can explain these things, i would be more than happy.
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1. Does audio quality also depend on the same ?
>> Very much so.. a simple example is mp3 - use less kb/s and you get worse quality.. The number of channels and the encoding format determine the bandwidth - there are different coding standards depending on the use. MP3,
AAC (used in iPOD), Dolby (various versions) are example of coding formats. Mono, stereo, surrond, 5.1 (5 channels plus sub woofer), 7.1 (7 channels + subwoofer) define the number of channels that need to be encoded and therefore more the number of channels, more bandwidth required. Typically HDTV broadcasts in the US are accompanies by 5.1 channels of sound. In india, the DTH operators offer "CD quality" stereo sound..
2. When DishTv is saying that the equipment they supply is capable of n number of channels, what is the minimum bandwidth required for each channel ?
>> You dont have a control on that, but they do. So overall for argument sake if they have 100Mbps transponder bandwitdh on the satellite, they could squeeze in around 18-19 channels @5Mbps each if they kept them all equal. The DTH operator, depending on the importance of the channel (premium or normal or just to fill space) and the amount of advertising revenue, and the type of content allocates bandwidth to each channel. It is a balance between number of channels and the number of transponders on the satellite as each transponder has x Mbps bandwidth. If you go below a minimum bandwidth, you will start to see/hear glitches - blockiness, picture freeze, audio clicks etc. are common examples of low bitrate. The other factor is the quality of the decoder (which sits on your STB).
3. Do sports channels require larger bandwidth ?
>> Yes, more action and movement and colour - more bandwidth.. Snooker will require less bandwidth than football..
4. How can i ensure that i get the best quality of picture & sound within the bandwidth allocated by dish ?
>> Unfortunately, it is not in your hands ;-(... It is upto the operator..All you can do is to ensure that from the dish to the STB and from the STB to your TV/Audio system, you use good quality cables that do not lower the quality further.
5. The signal strength is always around 72-75%, 75% being excellent picture quality. Is there anyway i can improve on that ?
>> Direction of the antenna towards the satellite, the location within India (different parts of the satellite footprint have different strengths), any obstructions (trees, buildings), rain are some factors that affect the signal strength..
Does that mean i can switch over to Tata Sky, if i am not satisfied with dish ??
>> Yes, if your STB that Dish gives you has a CI interface, and the interoperability testing has been done by the STB vendor.